General and efficient simulation of pulse EPR spectra

• Published in: Physical chemistry chemical physics : PCCP Vol. 11; no. 31; pp. 6614 - 6625
• Main Authors: STOLL, Stefan, BRITT, R. David
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2009
• Subjects: Algorithms; Chemistry; Computer Simulation; Electron Spin Resonance Spectroscopy; Exact sciences and technology; General and physical chemistry; Microwaves; Models, Chemical; Software; Histogram; Pulse; EPR spectrometry; Microwave; Electron transfer; Spin echo; Spin system; Simulation; Frequency; Calculation; Software; Resonance; EPR spectrum; Electrons
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/b907277b

We present a rather general and efficient method of simulating electron-spin echo spectra for spin systems where the microwave frequency does not simultaneously excite EPR transitions that share a common level. The approach can handle arbitrary pulse sequences with microwave pulses of arbitrary length and strength. The signal is computed as a sum over signals from the electron coherence transfer pathways contributing to the detected echo. For each pathway, amplitudes and frequencies of the signal components are computed and used to construct a spectral histogram from which the time-domain signal is obtained. For multinuclear spin systems, the nuclear subspace is factorized to accelerate the computation. The method is also applicable to high electron spin systems with significant zero-field splitting and to pulse electron-nuclear double resonance experiments. The method is implemented in the software package EasySpin, and several illustrative calculations are shown.